This invention relates to a system and method for regenerating alternating current for the purpose of producing a cleaner AC waveform, eliminating noise on the AC line and providing regulation and, more particularly, to such a system and method utilizing a tracking supply.
In many applications utilizing high-precision electrical components, it is desirable, if not necessary, that the source of AC power used to drive the components is at a constant voltage, so as not to compromise the performance of the components. In cases where the components are driven by ordinary house current that purports to supply 120 volts, variations in demands on the power grid supplying the voltage often cause this value to vary considerably.
Therefore, voltage regulator systems have evolved, many of which utilize autotransformers controlled by a motor or by switched taps. However, these systems are not without problems. For example, they can only correct the voltage in discrete steps and therefore do not completely eliminate the error between the desired voltage and the actual output. Also, they are inherently slow, and can only correct the voltage after it has been measured and determined to be wrong. Further, they do nothing to reduce harmonic distortion or noise and their circuitry increases the impedance of the power source.
Other regulation systems utilize power regenerators that create AC power from fixed DC supplies. However, these systems suffer primarily from extremely low efficiency, since the DC supplies are fixed, and have to be fairly high in magnitude in order to generate 120 VAC directly. The result is a great deal of voltage drop on the output devices. Also, the high voltages make MOSFET based switching designs impractical. Practical limitations (including efficiency and weight) make high power (>1000 W) systems unmanageable for the consumer electronics market.
Other regulation systems create a correction signal that is summed in with the AC input to create a “correct” output power waveform. These systems generally use an output transformer to sum the error signal, which increases the source impedance. They also rely on a measurement of the incoming voltage as a means of creating the error signal. This means the correction is limited by the capabilities of the error circuitry.
Therefore what is needed is a voltage regulation system that eliminates the above problems.